package analysis.syntaxtree;import analysis.visitors.TypeVisitor;import analysis.visitors.Visitor;public class IntegerType implements Type {  private static IntegerType instance = new IntegerType();  public static IntegerType instance() {    return instance;  }  private IntegerType() { }  public void accept(Visitor v) {    v.visit(this);  }  public Type accept(TypeVisitor v) {    return v.visit(this);  }  @Override  public String toString() {    return "int";  }}